This has nothing to do with Big Brother. The fried chicken thing has been part of a racial stereotype for years.
https://en.wikipedia.org/wiki/Stereo...ican_Americans
It's nothing new - the English mocked the Irish for eating potatoes, and the French mocked the English for only being able to cook roast beef, hence their disparaging nickname 'le rosbif'. There are lots more.
Racial stereotyping is so pervasive that a lot of people don't even realise they're doing it. Since Stone Age times, people have always shown hostility towards anything they saw as 'different'. To the perpetrator, it's usually seen as a bit of harmless fun, but to others it's a sign of ignorance.